Sizing compositions



Patented Apr. 16, 1946 aseacst srzmo COMPOSITIONS Arthur C. Dreshileld. Wilmington, to Hercules Powder Company,

DeL. assignmas Del., a corporation of Delaware No Drawing. Application September 3, 1941, Serial No. 409,362

11 Claims.

This invention relates to sizing compositions, and in particular concerns improved dry saponifled rosin sizes.

As is well known, saponifled rosin size may be prepared and utilized either in dry form or as a liquid or paste in admixture with water. The dry form is usually prepared by spray-drying saponifled or partially saponified rosin to form a light dry powder which is particularly adapted to use in sizing operations by reason of its ease and economy of shipment, rapid solution in water, and good sizing efficiency. This type of size, however, has a strong tendency to oxidize and spontaneously decompose in the presence of air, especially if it contains some free rosin or free alkali. Such oxidation and consequent heating is not only highly deleterious to the size itself but also presents a considerable fire hazard during storage and shipment. In addition to being unstable upon storage in the air, the dry rosin size heretofore known has the further disadvantage being inherently dusty and disagreeable to handle, particularly since it often contains a small proportion of free alkali. Because of their light dry fluffy nature, the size particles readily float in the air and thereby constitute an explosion hazard as well as a menace to the health of those who package or otherwise handle the size.

I have not found that dry rosin sizes comprising saponifled rosin or saponified abietic acid may be effectively stabilized against oxidation in the air by the addition of a minor proportion of a wax or wax-like material. Dry rosin sizes stabilized in this manner may be stored for relatively long periods of time without danger of decomposition by oxidation or spontaneous combustion. Furthermore, they are substantially non-dusty, and are hence safer and more agreeable to handie. These advantages are attained without decreasing the sizing efliciency of the size, and, as a matter of iact, the wax-containing dry sizes provided by the invention are in some respects superior in sizing value to the dry sizes heretofore known.

The wax or wax-like material employed in preparing the new dry sizing compositions may be a true wax such as carnauba wax, candelilla wax, ceresin wax, beeswax, montan wax, Japan wax, hydrogenated castor oil, etc., or, more preferably, it may be a wax-like hydrocarbon such as the crystalline, amorphous, or micro-crystalline parafiln waxes of varying melting point, crude scale wax, etc. Accordingly, it will be understood that the term wax as herein employed refers to such wax-like hydrocarbons of mineral origin as well as to the true vegetable waxes. Regardless of its nature, the wax is usually employed in an amount representing between about 15 and about 50, preferably between about 20 and about 35, per cent by weight of the entire composition, although the optimum proportion will depend somewhat upon the desired degree of stabilization, the type of size, i. e., whether it is substantially neutral or contains some free rosin or free alkali. and the desired sizing characteristics.

The dry saponifled rosin employed in the new compositions may be manufactured from any of the grades of wood or gum rosin, or mixtures thereof, or from rosin which has been partially polymerized by treatment with a, polymerization catalyst. The rosin may likewise be one which has been subjected t heat-treatment prior to saponiflcation to an extent sulllcient to reduce its tendency to form acid abietate salts but insufllcient to form decarboxylation products which are deleterious to sizing operations. Similarly, any caustic alkali, e. g., sodium or potassium hydroxide, may be employed as the saponilying agent. and the saponiflcation reaction may be carried out in such manner that the dry saponlfled product is substantially neutral or contains a moderate excess of tree alkali or free rosin.

Th'e sizing compositions provided by the invention may be prepared simply by mechanically mixing the wax in molten or finely-divided form with dry saponified rosin, although it will usually be found the. a more homogeneous and dustless product will be obtained if the wax is dded to the rosin before or during the saponiflcation reaction. A preferred mode of operatidn consists in incorporatin the wax with the size during preparation of the latter by the method described in U. S. Patent No. 2,134,912. Such method es sentially comprises introducing molten rosin and the desired proportion oi the wax into an autoclave and thereafter forcing a hot aqueous alkali solution of 25-50 per cent by weight concentration into the body of molten rosin under pressure while maintaining the mixture at a. temperature of about -190 C. and under its autogenic pressure. Upon completion of the saponiflcatlon reaction, the mixture is allowed to discharge under its own pressure into a chamber maintained at or below about 78 per cent relative humidity, whereby it is instantly desiccated to a dry non-caking powder having the wax unilormly dispersed therethrough. Alternatively, the wax may be forced into the autoclave after the injection of the alkali. The invention is not limited to such modes of operation, however, and

A mixture oi 20.2 parts by weight of G gum rosin, 10.8 parts by weight of I wood rosin, and 8.93 parts by weight of paramn wax (melting point 58-60 C.) was charged into an oiliacketed autoclave and heated to a temperature of 149 C., after which 3.83 parts by weight of sodium hydroxide in the form of a hot concentrated aqueous solution was forced in at the bottom of the autoclave under a pressure of about 120 lbs/sq. in. The mixture was heated at a temperature of 150-i'75 C. for a period oi 20 minutes while venting the autoclave to maintain a pressure of 80-110 lbs/sq. in., after which it was allowed to discharge at a temperature of 176 C. and under a pressure of 110 lbs/sq. in. into a large drying chamber. The sizing composition so obtained was substantially neutral and contained 20 per cent by weight oi the wax. It was considerably less dusty than a similar size which contained no wax. and had a 4-hour oxygen demand value of about 0.44 per cent. Ordinary dry saponifled rosin size has an average 4-hour oxygen demand value of about 3.7 per cent.

Example I! A mixture or 65 parts by weight of G gum rosin, 35 parts by weight of I wood rosin. and 28.8 parts by weight of paraiiln wax was saponiiled with 12.1 parts by weight of sodium hydroxide to form a dry size in a manner substantially the same as that described in Example I. In the same manner there was prepared a dry size from which the wax was omitted. The stability of each of these sizes to atmospheric oxidation was obtained by a determination 01' their 4-hour, 24- hour, and 48-hour oxygen demand values in an oxygen absorption train. These values were as follows: MM

Oxygen demand value,

P620811! Size composition 48-hour 4-hour I 24-hour 0. 21 Dry saponilimi rosin, l 2. l7

Lil) 7.88

A greater degree of stabilization in the wax-containing size may be obtained by employing a somewhat larger proportion, e. 3. 30-40 per cent by weight, oi the wax. Similar results may be obtained with other waxes and wax-like materials.

In addition to being considerably less dusty and more stable to oxidation than the dry saponlned rosin sizes heretofore known. the sizing compositions provided by the invention have the particular advantage of being capable of direct addition to the heater in the sizing operation without causing the formation of wax spots on the paper. Heretoi'ore, in sizing paper stock with wax and rosin size it has been deemed necessary either to form separate solutions or dispersions of the rosin size and wax and add them separately to the heater, or to resort to highly complicated dispersing methods. The use of the present compositions obviates the steps of forming and handling separate wax and size dispersions, and the use of special dispersing operations.

Other modes of applying the principle of the invention may be employed instead of those explains change being made as regards the materials or methods herein disclosed, provided the product stated by any of the following claims, or the equivalent of such stated product, be obtained.

What I claim and Patent is:

l. A non-dusty dry saponified rosin sizing composition readily dispersible in water and resistant to oxidation in the air, comprising saponiiled rosin in the form of a. dry powder and, as the only added material increasing the resistance 01' the saponified rosin to oxidation in the air, a wax incorporated with the saponified rosin in an amount representing between about 15% and about 50% by weight of the entire composition, said wax serving to increase the resistance of the saponliied rosin to oxidation in the air and to render it substantially non-dusty.

2. A non-dusty dry saponifled rosin sizing composition readily dispersible in water and resistant to oxidation in the air, comprising saponifled rosin in the form of a dry powder and, as the only added material increasing the resistance of the saponifled rosin to oxidation in the air, a wax incorporated with the saponifled rosin in an amount representing between about 20% and about 35% by weight of the entire composition, said wax serving to increase the resistance of the saponified rosin to oxidation in the air and to render it substantially non-dusty.

3. A non-dusty dry saponified rosin sizing composition readily dlspersible in water and resistant to oxidation in the air, comprising saponlfled rosin in the form oia dry powder and, as the only added material increasing the resistance of the saponifled rosin to oxidation in the airra wax-like hydrocarbon incorporated with the saponiiled rosin in an amount representing between about l5% and about 50% by weight of the entire composition, said wax-like hydrocarbon serving to increase the resistance 01' the saponifled rosin to oxidation in the air and to render it substantially non-dusty.

4,. A non-dusty dry saponifled rosin sizing composition readily dispersible to oxidation in the air,

desire to protect by Letters comprising saponiiied rosin in the form of a dry powder and, as the only added material increasing the resistance of the saponifled rosin to oxidation in the air, a wax-like hydrocarbon incorporated withthe saponified rosin in an amount representing between about 20% and about 35% by weight of the entire composition, said wax-like hydrocarbon serving to increase the resistance of the saponifled rosin to oxidation in the air and to render it substantially non-dusty.

5. A non-dusty dry saponifled rosin sizing composition readily dispersible in water and resistant to oxidation in the air, comprising saponifled rosin in the form 01' a dry powder and, as the only added material increasing the resistance or the saponlfled rosin to oxidation in the air, a paraflln wax incorporated with the saponified rosin in an amount representing between about 15% and about 50% byweight oi the entire composition, said paraffin wax serving to increase the resistance of the saponified rosin to oxidation in the air an to render it substantially nondusty.

in water and resistant V 6. A non-dusty dry saponifled rosin sizing composition readily dispersible in water and resistant to oxidation in the air, comprising saponifled rosin in the form oi a dry powder and, as the only added material increasing the resistance of the saponiiied rosin to'oxidation in the air, a paraflin wax incorporated with the saponiiied rosin in an amount representing between about 20% and about 35% by weight of the entire composition, said paraflin wax serving to increase the resistance of the saponified rosin to oxidation in the air and to render it substantially nondusty.

7. A non-dusty dry saponified rosin sizing composition readily dispersible in water and resistant to oxidation in the air, comprising substantially neutral saponified rosin in the form of a dry powder and, as the only added material increasing the resistance of the saponiiied rosin to oxidation in the air, a wax incorporated with the saponiiied rosin in an amount representing between about 15% and about 50% by weight of the entire composition, said wax serving to increase the resistance of the saponiiied rosin to oxidation in the air and to render it substantially non-dusty.

8. A non-dusty dry saponifled rosin sizing composition readily dispersible in water and resistant to oxidation in the air, comprising substantially neutral saponifled rosin in the form of a dry powder and, as the only added material increas-' ing the resistance of the saponifled rosin to oxidation in the air, a paraffin wax incorporated with the saponifled resin in an amount representing between about 15% and about 50% by weight or the entire composition, said paraflin wax serving to increase the resistance of the saponified rosin to oxidation in the air and to render it substantially non-dusty.

9. A non-dusty dry saponiiied rosin sizing composition readily dispersible in water and resistant to oxidation in the air, comprising substantially neutral saponifled rosin in the form of a dry powder and, as the only added material increasing the resistance of the saponifled rosin to oxidation in the air, a paraflin wax incorporated with the saponifled rosin in an amount representing between about 20% and about by weight oi the entire composition. said wax serving to increase the resistance of the saponiiied rosin to oxidation in the .air and to render it substantially non-dusty.

10. A non-.dusty dry saponifled rosin sizing composition readily dispersible in water and resistant to oxidation in the air, comprising saponifled rosin, tree alkali, and, as the only added material increasing the resistance of the saponifled rosin to oxidation in the air, a wax incorporated with the saponifled rosin in an amount repre-, senting between about 15% and about by weight of the entire composition, said wax serving t increase the resistance of the saponiiied rosin to oxidation in the air and to render it substantially non-dusty.

11. A non-dusty dry saponifled rosin sizing composition readily dispersible in water and resistant to oxidation in the air, comprising saponifled rosin, free alkali, and, as the only added material increasing the resistance of the saponifled rosin to oxidation in the air, a parailin wax incorporated with the saponiiied resin in an amount representing between about 20% and about 35% by weight 0! the entire composition, said paraflin wax serving to increase the resistance of the saponiiied main to oxidation in the air and to render it substantially non-dusty.

Certificate oi Correction Patent No. 2,398,699.

April 16, 1946.

ARTHUR C. DRESHFIELD It is hereby certified that error appears in the numbered patent requiring correction as follows: age 1,

s ecification of the above 5st column, line 29, for

not found read now found; and thatthe said Letters Patent should be with this correction therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 4th day of June, A. D. 1946.

Fem AIM Oomms'sn'ma of Pm.

V 6. A non-dusty dry saponifled rosin sizing composition readily dispersible in water and resistant to oxidation in the air, comprising saponifled rosin in the form oi a dry powder and, as the only added material increasing the resistance of the saponiiied rosin to'oxidation in the air, a paraflin wax incorporated with the saponiiied rosin in an amount representing between about 20% and about 35% by weight of the entire composition, said paraflin wax serving to increase the resistance of the saponified rosin to oxidation in the air and to render it substantially nondusty.

7. A non-dusty dry saponified rosin sizing composition readily dispersible in water and resistant to oxidation in the air, comprising substantially neutral saponified rosin in the form of a dry powder and, as the only added material increasing the resistance of the saponiiied rosin to oxidation in the air, a wax incorporated with the saponiiied rosin in an amount representing between about 15% and about 50% by weight of the entire composition, said wax serving to increase the resistance of the saponiiied rosin to oxidation in the air and to render it substantially non-dusty.

8. A non-dusty dry saponifled rosin sizing composition readily dispersible in water and resistant to oxidation in the air, comprising substantially neutral saponifled rosin in the form of a dry powder and, as the only added material increas-' ing the resistance of the saponifled rosin to oxidation in the air, a paraffin wax incorporated with the saponifled resin in an amount representing between about 15% and about 50% by weight or the entire composition, said paraflin wax serving to increase the resistance of the saponified rosin to oxidation in the air and to render it substantially non-dusty.

9. A non-dusty dry saponiiied rosin sizing composition readily dispersible in water and resistant to oxidation in the air, comprising substantially neutral saponifled rosin in the form of a dry powder and, as the only added material increasing the resistance of the saponifled rosin to oxidation in the air, a paraflin wax incorporated with the saponifled rosin in an amount representing between about 20% and about by weight oi the entire composition. said paraflin wax serving to increase the resistance of the saponiiied rosin to oxidation in the .air and to render it substantially non-dusty.

10. A non-.dusty dry saponifled rosin sizing composition readily dispersible in water and resistant to oxidation in the air, comprising saponifled rosin, tree alkali, and, as the only added material increasing the resistance of the saponifled rosin to oxidation in the air, a wax incorporated with the saponifled rosin in an amount repre-, senting between about 15% and about by weight of the entire composition, said wax serving t increase the resistance of the saponiiied rosin to oxidation in the air and to render it substantially non-dusty.

11. A non-dusty dry saponifled rosin sizing composition readily dispersible in water and resistant to oxidation in the air, comprising saponifled rosin, free alkali, and, as the only added material increasing the resistance of the saponifled rosin to oxidation in the air, a parailin wax incorporated with the saponiiied resin in an amount representing between about 20% and about 35% by weight 0! the entire composition, said paraflin wax serving to increase the resistance of the saponiiied main to oxidation in the air and to render it substantially non-dusty.

sn'raurt c. pamnrmn.

Certificate oi Correction Patent No. 2,398,699.

April 16, 1946.

ARTHUR C. DRESHFIELD It is hereby certified that error appears in the numbered patent requiring correction as follows: age 1,

s ecification of the above 5st column, line 29, for

not found read now found; and thatthe said Letters Patent should be with this correction therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 4th day of June, A. D. 1946.

Fem AIM Oomms'sn'ma of Pm. 

